U.S. Meat Animal Research Center, ARS-USDA, Clay Center, NE 68933, USA.
J Anim Sci. 2012 Aug;90(8):2515-23. doi: 10.2527/jas.2012-4723.
Selection for 11 generations in swine for ovulation rate (OR) or uterine capacity (UC) resulted in significant changes in component traits of litter size. Our objective was to conserve the unique germplasm for the future and to characterize sperm quality as a correlated response to the selection criterion imposed compared with an unselected control line (CO). Boars representing genetic diversity available in all 3 lines were produced in 2 farrowing seasons. Season 1 was born in September 2005 and was sampled for semen characteristics in October 2006. Season 2 was born in March 2006 and was sampled for semen characteristics in February and March 2007. Each boar (n = 60) was collected twice. The sperm-rich fraction was obtained, and volume and concentration of sperm cells were measured to estimate total sperm production. Each ejaculate was extended 1:3 (vol/vol) with Androhep Plus (Minitube, Verona, WI) and was packed for shipping to the National Animal Germplasm Program laboratory for processing into frozen straws. Semen quality was measured by computer-assisted semen analysis at 3 semen processing points: fresh (FR), 24 h after extender added (E), and postthaw (PT). A mixed model ANOVA was applied to the data. Fixed effects of farrowing season, line, and 2-way interactions were fitted. The random effect of boar (n = 60) within farrowing season and line was used to test line differences. Sperm concentration was not different (P = 0.18) among the lines (0.594 × 10(9), 0.691 × 10(9), and 0.676 × 10(9) cells/mL for CO, OR, and UC lines, respectively). However, significance (P = 0.04) was detected for the volume of the sperm-rich fraction, greatest for OR (86.4 mL), intermediate for UC (75.5 mL), and least for CO (70.2 mL). Line differences were thus detected (P = 0.02) for total sperm production per ejaculate, greatest for OR (54.9 × 10(9)), intermediate for UC (48.7 × 10(9)), and least for CO (40.5 × 10(9)). A larger percentage of progressively motile sperm and greater estimates of sperm velocity only at processing point E (P < 0.01) were detected in favor of CO. Estimates of motility, velocity, and other parameters of sperm movement measured on E processing points were positively correlated with the same estimates obtained PT, but the magnitude was low to moderate (r range -0.03 to 0.23). Thus, selection for component traits of female reproduction had a favorable effect on total sperm production of boars.
经过 11 个世代对猪的排卵率（OR）或子宫容量（UC）进行选择，导致产仔数的组成性状发生了显著变化。我们的目标是为未来保存独特的种质资源，并将精子质量特征作为与选择标准相关的响应进行特征描述，与未选择的对照系（CO）相比。在两个分娩季节中生产了代表所有 3 个系中遗传多样性的公猪。第 1 季于 2005 年 9 月出生，并于 2006 年 10 月采样精液特征。第 2 季于 2006 年 3 月出生，并于 2007 年 2 月和 3 月采样精液特征。每头公猪（n=60）采集两次。获得富含精子的部分，并测量精子细胞的体积和浓度以估计总精子产生量。每个精液样本都用 Androhep Plus（Minitube，Verona，WI）按 1:3（体积/体积）的比例进行扩展，并包装运往国家动物种质资源计划实验室进行处理，制成冷冻 straws。通过计算机辅助精液分析在 3 个精液处理点测量精液质量：新鲜（FR），添加扩展剂后 24 小时（E）和解冻后（PT）。应用混合模型方差分析对数据进行分析。拟合了分娩季节、系和 2 个因素的固定效应。分娩季节和系内的公猪随机效应（n=60）用于测试系间差异。精子浓度在系间没有差异（P=0.18）（CO、OR 和 UC 系分别为 0.594×10（9）、0.691×10（9）和 0.676×10（9）细胞/mL）。然而，精子富积部分的体积具有显著性（P=0.04），OR 最大（86.4mL），UC 居中（75.5mL），CO 最小（70.2mL）。因此，检测到总精子产生量的系间差异（P=0.02），OR 最大（54.9×10（9）），UC 居中（48.7×10（9）），CO 最小（40.5×10（9））。在处理点 E 时，检测到更高比例的渐进运动精子和更大的精子速度估计值（P<0.01），这有利于 CO。在 E 处理点测量的运动性、速度和其他精子运动参数的估计值与解冻后（PT）获得的相同估计值呈正相关，但幅度较低到中等（r 范围为-0.03 到 0.23）。因此，对雌性繁殖组成性状的选择对公猪的总精子产生有有利影响。
